python学习笔记2

创建一个文件并往里面写入内容

import os

# coding='utf-8'

#取得OS的换行符

ls = os.linesep



# 获取文件名

while True:

    fname = raw_input('input file name: ')

    if os.path.exists(fname):

        print "ERROR : '%s' already exists!" % fname

    else:

        break

print fname

#获取文件的内容

all = []

print "\nEnter lines('.' by iteslf to quit).\n"



#读取用户的输入

while True:

    entry = raw_input('> ')

    if entry == '.':

        break

    else:

        all.append(entry)



#写入文件

fobj = open(fname,'w')

fobj.writelines(['%s%s' % (x, ls ) for x in all])

fobj.close()

print "DONE"

读取文件内容并显示出来

# coding='utf-8'

# 获取文件名

fname = raw_input('input file name: ')

print fname



try:

    fobj = open(fname,'r')

except IOError, e:

    print "**** file open: ",e

else:

    for eachLine in fobj:

        print eachLine,

    fobj.close();

获取数值的类型.注意python作为高级语言,却没有对数值进行统一,还是分属于几个类型:整型,浮点型,长整型,复数

# coding='utf-8'

# 获取数值的类型

def getNumType(num):

    print num, 'is',

    #判定参数一是否为参数二当中的某个元素的实例

    if isinstance(num, (int,long,float,complex)):

        print 'a number of type: ',type(num).__name__

    else:

        print 'not a number at all'

        

getNumType(-68)

getNumType(99999999999999999999999999999L)

getNumType(98.6)

getNumType(-5.2+1.9j)

getNumType("1212")